www.google.com/… map of the destruction (crowd sourced locations google map)
Mark Sumner also has a diary up but I’ve decided to blog about this as well as I’m an architect and have quite a bit of interest/knowledge re: the subject. (Also some time today)
This looks very bad. Dust indicates bldg collpases. Mexico City has very bad soil conditions which exacerbated the 1985 quake, as well as there being bad structural configurations of some of the building failures then.
I’ll continue to update
Below is one of the worst scenarios- indicates “soft story” failure- usually the bottom floor of modern designs where building is full of open doors/windows and no solid walls to brace/resist shaking. Also tend to be taller floors which means tendency for columns to snap at that level. Also, worst of all: point of most intense shear forces if ground accelerations are side to side.
1950’s-70’s structures are most vulnerable to the bottom story failure:
and another:
Not all bad news, these two building’s flexibility helped them to successfully ride it out:
Interesting note: The above and below buildings are only 200 meters apart, just north of Paseo de la Reforma. The above bldg is oriented perpendicular to the ground waves, and the below is in line with them. You can see the top one especially rocking side to side at its top front floor. The below bldg moves less because it better resisting the movement along its long axis. But it’s also why the side walls are crumbling out of their frames as the rectangular shapes are racked out of square.
Heartbreaking, can only hope for best...
This is not a good sign. A one story industrial/retail bldg did not make it
Terrible exterior cladding performance below. This would not happen in a more modern/code compliant bldg. (this is the national employment service /servicio nacional de empleo)
Below, besides the obvious water waves, note the trees swaying
Gas fires and explosions. There are apparently a lot of these.
Not sure where outside the city this was but it must have been close to the epicenter for the highway bridge to collapse. They are typically very simple and robust structures,
Hear hear on this sentiment:
and 21st Century schizoid man weighs in: